Antibacterial effect of probiotic lactic acid bacteria on some pathogens

Abstract

Lactic acid bacteria (LAB) are a group of gram positive bacteria including the genera Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Streptococcus. The general description of bacteria included in the group is gram – positive, no spore forming, cocci or rods, which produce lactic acid as the major end product during the fermentation of carbohydrates. Recent taxonomic revisions of these genera suggest that lactic acid bacteria comprise the genus Enterococcus (Rattanachaikunsopon and Phumkhachorn, 2010).  The aim of this study was to investigate the antibacterial activity of bacterian isolated from (fermented cucumber, infant stool, environmental) samples towards some pathogenic bacteria. Not concentrated and concentrated CFSS of EE had no activity on all the test bacteria except Staphylococcus aureus which was sensitive to CFS3 only. All CFSS of the normal flora Enterococcus feacalis inhibited all the tested pathogenic, the diameters of the inhibition zones were varied. All CFSS of Lactobacillus displayed numerous antibacterial activity against all test bacteria. The antibacterial activity increased by increasing the concentration of CFS. This study confirmed the presence of probiotic action of lactobacilli isolates Gram + ve bacteria (Staphylococcus aureus) are highly sensitive in compared to Gram - ve (Pseudomonas aeruginosa, E. coli).